Why do we remember some things and not others? In a unique imaging study, published in the journal Nature, researchers have discovered how neurons in the brain might allow some experiences to be remembered while others are forgotten. It turns out, if you want to remember something about your environment, you better involve your dendrites.
Using a high-resolution, one-of-a-kind microscope, researchers peered into the brain of a living animal and saw exactly what was happening in individual neurons called place cells as the animal navigated a virtual reality maze. The scientists found that, contrary to current thought, the activity of a neuron's cell body and its dendrites can be different. They observed that when cell bodies were activated but the dendrites were not activated during an animal's experience, a lasting memory of that experience was not formed by the neurons. This suggests that the cell body seems to represent ongoing experience, while dendrites, the treelike branches of a neuron, help to store that experience as a memory.
In the brain's hippocampus, there are hundreds of thousands of place cells, neurons essential to the brain's GPS system. The researchers are the first to image the activity of individual dendrites in place cells.
Their findings contribute to our understanding of how the brain represents the world around it and also point to dendrites as a new potential target for therapeutics to combat memory deficits and debilitating diseases, such as Alzheimer's disease (AD). Disruption to the brain's GPS system is one of the first symptoms of AD, with many patients unable to find their way home. Understanding how place cells and their dendrites store these types of memories could help us find new ways to treat the disease.